yamllint version 1.26.3

This reverts commit 8f68248 "Remove runtime dep 'setuptools' for Python
< 3.8". It looks like removing setuptools induces problems on some
systems, see for example the linked discussion.

Fixes https://github.com/adrienverge/yamllint/issues/380.

.github/workflows/ci.yaml

@@ -0,0 +1,54 @@
+---
+
+name: CI
+
+on:  # yamllint disable-line rule:truthy
+  push:
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  lint:
+    name: Linters
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.9
+      - run: python -m pip install flake8 flake8-import-order doc8 sphinx
+      - run: python -m pip install .
+      - run: flake8 .
+      - run: doc8 $(git ls-files '*.rst')
+      - run: yamllint --strict $(git ls-files '*.yaml' '*.yml')
+      - run: python setup.py build_sphinx
+
+  test:
+    name: Tests
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version:
+          - 3.5
+          - 3.6
+          - 3.7
+          - 3.8
+          - 3.9
+          - nightly
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Python ${{ matrix.pyver }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.pyver }}
+      - name: Fix GitHub Actions path
+        run: echo /home/runner/.local/bin >>$GITHUB_PATH
+      - run: pip install coveralls
+      - run: pip install .
+      - run: coverage run --source=yamllint -m unittest discover
+      - name: Coveralls
+        uses: AndreMiras/coveralls-python-action@develop

.travis.yml

@@ -1,28 +0,0 @@
----
-dist: xenial  # required for Python >= 3.7 (travis-ci/travis-ci#9069)
-language: python
-python:
-  - 2.7
-  - 3.5
-  - 3.6
-  - 3.7
-  - 3.8
-  - nightly
-env:
-  - REMOVE_LOCALES=false
-  - REMOVE_LOCALES=true
-install:
-  - pip install pyyaml coveralls flake8 flake8-import-order doc8
-  - if [[ $TRAVIS_PYTHON_VERSION != 2* ]]; then pip install sphinx; fi
-  - pip install .
-  - if [[ $REMOVE_LOCALES = "true" ]]; then sudo rm -rf /usr/lib/locale/*; fi
-script:
-  - if [[ $TRAVIS_PYTHON_VERSION != nightly ]]; then flake8 .; fi
-  - if [[ $TRAVIS_PYTHON_VERSION != 2* ]]; then doc8 $(git ls-files '*.rst'); fi
-  - yamllint --strict $(git ls-files '*.yaml' '*.yml')
-  - coverage run --source=yamllint setup.py test
-  - if [[ $TRAVIS_PYTHON_VERSION != 2* ]]; then
-      python setup.py build_sphinx;
-    fi
-after_success:
-  coveralls

CHANGELOG.rst

@@ -1,11 +1,37 @@
 Changelog
 =========
 
+1.26.3 (2021-08-21)
+-------------------
+
+- Restore runtime dependency ``setuptools`` for Python < 3.8
+
+1.26.2 (2021-08-03)
+-------------------
+
+- Fix ``python_requires`` to comply with PEP 345 and PEP 440
+
+1.26.1 (2021-04-06)
+-------------------
+
+- Remove runtime dependency ``setuptools`` for Python < 3.8
+- Fix ``line_length`` to skip all hash signs starting comment
+
+1.26.0 (2021-01-29)
+-------------------
+
+- End support for Python 2 and Python 3.4, add support for Python 3.9
+- Add ``forbid: non-empty`` option to ``braces`` and ``brackets`` rules
+- Fix ``quoted-strings`` for explicit octal recognition
+- Add documentation for integration with Arcanist
+- Fix typos in changelog and README
+- Stop using deprecated ``python setup.py test`` in tests
+
 1.25.0 (2020-09-29)
 -------------------
 
 - Run tests on Travis both with and without UTF-8 locales
-- Improve documentationon with default values to rules with options
+- Improve documentation with default values to rules with options
 - Improve documentation with a Python API usage example
 - Fix documentation on ``commas`` examples
 - Packaging: move setuptools' configuration from ``setup.py`` to ``setup.cfg``

CONTRIBUTING.rst

@@ -13,7 +13,9 @@ Pull Request Process
 
    .. code:: bash
 
-    python setup.py test
+    pip install --user .
+    python -m unittest discover  # all tests...
+    python -m unittest tests/rules/test_commas.py  # or just some tests (faster)
 
 3. If you add code that should be tested, add tests.
 

README.rst

@@ -19,11 +19,7 @@ indentation, etc.
    :target: https://yamllint.readthedocs.io/en/latest/?badge=latest
    :alt: Documentation status
 
-Written in Python (compatible with Python 2 & 3).
-
-⚠ Python 2 upstream support stopped on January 1, 2020. yamllint will keep
-best-effort support for Python 2.7 until January 1, 2021. Passed that date,
-yamllint will drop all Python 2-related code.
+Written in Python (compatible with Python 3 only).
 
 Documentation
 -------------

docs/integration.rst

@@ -51,3 +51,22 @@ An example workflow using GitHub Actions:
 
          - name: Lint YAML files
            run: yamllint .
+
+Integration with Arcanist
+-------------------------
+
+You can configure yamllint to run on ``arc lint``. Here is an example
+``.arclint`` file that makes use of this configuration.
+
+.. code:: json
+
+  {
+    "linters": {
+      "yamllint": {
+        "type": "script-and-regex",
+        "script-and-regex.script": "yamllint",
+        "script-and-regex.regex": "/^(?P<line>\\d+):(?P<offset>\\d+) +(?P<severity>warning|error) +(?P<message>.*) +\\((?P<name>.*)\\)$/m",
+        "include": "(\\.(yml|yaml)$)"
+      }
+    }
+  }

setup.cfg

@@ -26,14 +26,12 @@ classifiers =
   Environment :: Console
   Intended Audience :: Developers
   License :: OSI Approved :: GNU General Public License v3 (GPLv3)
-  Programming Language :: Python :: 2
-  Programming Language :: Python :: 2.7
   Programming Language :: Python :: 3
-  Programming Language :: Python :: 3.4
   Programming Language :: Python :: 3.5
   Programming Language :: Python :: 3.6
   Programming Language :: Python :: 3.7
   Programming Language :: Python :: 3.8
+  Programming Language :: Python :: 3.9
   Topic :: Software Development
   Topic :: Software Development :: Debuggers
   Topic :: Software Development :: Quality Assurance
@@ -48,7 +46,7 @@ project_urls =
 [options]
 packages = find:
 
-python_requires = >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*
+python_requires = >=3.5
 
 include_package_data = True
 install_requires =
@@ -69,3 +67,6 @@ yamllint = conf/*.yaml
 [options.entry_points]
 console_scripts =
   yamllint = yamllint.cli:run
+
+[coverage:run]
+relative_files = True

tests/rules/test_braces.py

@@ -61,6 +61,30 @@ class ColonTestCase(RuleTestCase):
                    '  a: 1\n'
                    '}\n', conf, problem=(2, 8))
 
+        conf = ('braces:\n'
+                '  forbid: non-empty\n')
+        self.check('---\n'
+                   'dict:\n'
+                   '  a: 1\n', conf)
+        self.check('---\n'
+                   'dict: {}\n', conf)
+        self.check('---\n'
+                   'dict: {\n'
+                   '}\n', conf)
+        self.check('---\n'
+                   'dict: {\n'
+                   '# commented: value\n'
+                   '# another: value2\n'
+                   '}\n', conf)
+        self.check('---\n'
+                   'dict: {a}\n', conf, problem=(2, 8))
+        self.check('---\n'
+                   'dict: {a: 1}\n', conf, problem=(2, 8))
+        self.check('---\n'
+                   'dict: {\n'
+                   '  a: 1\n'
+                   '}\n', conf, problem=(2, 8))
+
     def test_min_spaces(self):
         conf = ('braces:\n'
                 '  max-spaces-inside: -1\n'

tests/rules/test_brackets.py

@@ -60,6 +60,29 @@ class ColonTestCase(RuleTestCase):
                    '  b\n'
                    ']\n', conf, problem=(2, 9))
 
+        conf = ('brackets:\n'
+                '  forbid: non-empty\n')
+        self.check('---\n'
+                   'array:\n'
+                   '  - a\n'
+                   '  - b\n', conf)
+        self.check('---\n'
+                   'array: []\n', conf)
+        self.check('---\n'
+                   'array: [\n\n'
+                   ']\n', conf)
+        self.check('---\n'
+                   'array: [\n'
+                   '# a comment\n'
+                   ']\n', conf)
+        self.check('---\n'
+                   'array: [a, b]\n', conf, problem=(2, 9))
+        self.check('---\n'
+                   'array: [\n'
+                   '  a,\n'
+                   '  b\n'
+                   ']\n', conf, problem=(2, 9))
+
     def test_min_spaces(self):
         conf = ('brackets:\n'
                 '  max-spaces-inside: -1\n'

tests/rules/test_line_length.py

@@ -14,9 +14,6 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import sys
-import unittest
-
 from tests.common import RuleTestCase
 
 
@@ -119,6 +116,27 @@ class LineLengthTestCase(RuleTestCase):
                    'long_line: http://localhost/very/very/long/url\n'
                    '...\n', conf, problem=(2, 21))
 
+        conf = 'line-length: {max: 20, allow-non-breakable-words: true}'
+        self.check('---\n'
+                   '# http://www.verylongurlurlurlurlurlurlurlurl.com\n'
+                   'key:\n'
+                   '  subkey: value\n', conf)
+        self.check('---\n'
+                   '## http://www.verylongurlurlurlurlurlurlurlurl.com\n'
+                   'key:\n'
+                   '  subkey: value\n', conf)
+        self.check('---\n'
+                   '# # http://www.verylongurlurlurlurlurlurlurlurl.com\n'
+                   'key:\n'
+                   '  subkey: value\n', conf,
+                   problem=(2, 21))
+        self.check('---\n'
+                   '#A http://www.verylongurlurlurlurlurlurlurlurl.com\n'
+                   'key:\n'
+                   '  subkey: value\n', conf,
+                   problem1=(2, 2, 'comments'),
+                   problem2=(2, 21, 'line-length'))
+
         conf = ('line-length: {max: 20, allow-non-breakable-words: true}\n'
                 'trailing-spaces: disable')
         self.check('---\n'
@@ -159,7 +177,6 @@ class LineLengthTestCase(RuleTestCase):
                    '  {% this line is' + 99 * ' really' + ' long %}\n',
                    conf, problem=(3, 81))
 
-    @unittest.skipIf(sys.version_info < (3, 0), 'Python 2 not supported')
     def test_unicode(self):
         conf = 'line-length: {max: 53}'
         self.check('---\n'

tests/rules/test_quoted_strings.py

@@ -436,3 +436,21 @@ class QuotedTestCase(RuleTestCase):
                    '- foo bar\n'
                    '- "foo bar"\n',
                    conf, problem1=(3, 3), problem2=(7, 3), problem3=(11, 3))
+
+    def test_octal_values(self):
+        conf = 'quoted-strings: {required: true}\n'
+
+        self.check('---\n'
+                   '- 100\n'
+                   '- 0100\n'
+                   '- 0o100\n'
+                   '- 777\n'
+                   '- 0777\n'
+                   '- 0o777\n'
+                   '- 800\n'
+                   '- 0800\n'
+                   '- 0o800\n'
+                   '- "0800"\n'
+                   '- "0o800"\n',
+                   conf,
+                   problem1=(9, 3), problem2=(10, 3))

tests/test_cli.py

@@ -14,10 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from io import StringIO
+from io import StringIO
 import fcntl
 import locale
 import os
@@ -246,19 +243,19 @@ class CommandLineTestCase(unittest.TestCase):
             cli.run(())
         self.assertNotEqual(ctx.returncode, 0)
         self.assertEqual(ctx.stdout, '')
-        self.assertRegexpMatches(ctx.stderr, r'^usage')
+        self.assertRegex(ctx.stderr, r'^usage')
 
         with RunContext(self) as ctx:
             cli.run(('--unknown-arg', ))
         self.assertNotEqual(ctx.returncode, 0)
         self.assertEqual(ctx.stdout, '')
-        self.assertRegexpMatches(ctx.stderr, r'^usage')
+        self.assertRegex(ctx.stderr, r'^usage')
 
         with RunContext(self) as ctx:
             cli.run(('-c', './conf.yaml', '-d', 'relaxed', 'file'))
         self.assertNotEqual(ctx.returncode, 0)
         self.assertEqual(ctx.stdout, '')
-        self.assertRegexpMatches(
+        self.assertRegex(
             ctx.stderr.splitlines()[-1],
             r'^yamllint: error: argument -d\/--config-data: '
             r'not allowed with argument -c\/--config-file$'
@@ -269,21 +266,21 @@ class CommandLineTestCase(unittest.TestCase):
             cli.run(('-', 'file'))
         self.assertNotEqual(ctx.returncode, 0)
         self.assertEqual(ctx.stdout, '')
-        self.assertRegexpMatches(ctx.stderr, r'^usage')
+        self.assertRegex(ctx.stderr, r'^usage')
 
     def test_run_with_bad_config(self):
         with RunContext(self) as ctx:
             cli.run(('-d', 'rules: {a: b}', 'file'))
         self.assertEqual(ctx.returncode, -1)
         self.assertEqual(ctx.stdout, '')
-        self.assertRegexpMatches(ctx.stderr, r'^invalid config: no such rule')
+        self.assertRegex(ctx.stderr, r'^invalid config: no such rule')
 
     def test_run_with_empty_config(self):
         with RunContext(self) as ctx:
             cli.run(('-d', '', 'file'))
         self.assertEqual(ctx.returncode, -1)
         self.assertEqual(ctx.stdout, '')
-        self.assertRegexpMatches(ctx.stderr, r'^invalid config: not a dict')
+        self.assertRegex(ctx.stderr, r'^invalid config: not a dict')
 
     def test_run_with_config_file(self):
         with open(os.path.join(self.wd, 'config'), 'w') as f:
@@ -300,6 +297,7 @@ class CommandLineTestCase(unittest.TestCase):
             cli.run(('-c', f.name, os.path.join(self.wd, 'a.yaml')))
         self.assertEqual(ctx.returncode, 1)
 
+    @unittest.skipIf(os.environ.get('GITHUB_RUN_ID'), '$HOME not overridable')
     def test_run_with_user_global_config_file(self):
         home = os.path.join(self.wd, 'fake-home')
         dir = os.path.join(home, '.config', 'yamllint')
@@ -386,7 +384,7 @@ class CommandLineTestCase(unittest.TestCase):
         with RunContext(self) as ctx:
             cli.run(('--version', ))
         self.assertEqual(ctx.returncode, 0)
-        self.assertRegexpMatches(ctx.stdout + ctx.stderr, r'yamllint \d+\.\d+')
+        self.assertRegex(ctx.stdout + ctx.stderr, r'yamllint \d+\.\d+')
 
     def test_run_non_existing_file(self):
         path = os.path.join(self.wd, 'i-do-not-exist.yaml')
@@ -395,7 +393,7 @@ class CommandLineTestCase(unittest.TestCase):
             cli.run(('-f', 'parsable', path))
         self.assertEqual(ctx.returncode, -1)
         self.assertEqual(ctx.stdout, '')
-        self.assertRegexpMatches(ctx.stderr, r'No such file or directory')
+        self.assertRegex(ctx.stderr, r'No such file or directory')
 
     def test_run_one_problem_file(self):
         path = os.path.join(self.wd, 'a.yaml')

tests/test_config.py

@@ -14,10 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from io import StringIO
+from io import StringIO
 import os
 import shutil
 import sys
@@ -48,7 +45,7 @@ class SimpleConfigTestCase(unittest.TestCase):
             config.YamlLintConfig('not: valid: yaml')
 
     def test_unknown_rule(self):
-        with self.assertRaisesRegexp(
+        with self.assertRaisesRegex(
                 config.YamlLintConfigError,
                 'invalid config: no such rule: "this-one-does-not-exist"'):
             config.YamlLintConfig('rules:\n'
@@ -67,7 +64,7 @@ class SimpleConfigTestCase(unittest.TestCase):
         self.assertEqual(c.rules['colons']['max-spaces-after'], 1)
 
     def test_unknown_option(self):
-        with self.assertRaisesRegexp(
+        with self.assertRaisesRegex(
                 config.YamlLintConfigError,
                 'invalid config: unknown option "abcdef" for rule "colons"'):
             config.YamlLintConfig('rules:\n'
@@ -105,7 +102,7 @@ class SimpleConfigTestCase(unittest.TestCase):
         self.assertEqual(c.rules['indentation']['check-multi-line-strings'],
                          False)
 
-        with self.assertRaisesRegexp(
+        with self.assertRaisesRegex(
                 config.YamlLintConfigError,
                 'invalid config: option "indent-sequences" of "indentation" '
                 'should be in '):

tests/test_module.py

@@ -47,16 +47,15 @@ class ModuleTestCase(unittest.TestCase):
             subprocess.check_output([PYTHON, '-m', 'yamllint'],
                                     stderr=subprocess.STDOUT)
         self.assertEqual(ctx.exception.returncode, 2)
-        self.assertRegexpMatches(ctx.exception.output.decode(),
-                                 r'^usage: yamllint')
+        self.assertRegex(ctx.exception.output.decode(), r'^usage: yamllint')
 
     def test_run_module_on_bad_dir(self):
         with self.assertRaises(subprocess.CalledProcessError) as ctx:
             subprocess.check_output([PYTHON, '-m', 'yamllint',
                                      '/does/not/exist'],
                                     stderr=subprocess.STDOUT)
-        self.assertRegexpMatches(ctx.exception.output.decode(),
-                                 r'No such file or directory')
+        self.assertRegex(ctx.exception.output.decode(),
+                         r'No such file or directory')
 
     def test_run_module_on_file(self):
         out = subprocess.check_output(

yamllint/__init__.py

@@ -22,7 +22,7 @@ indentation, etc."""
 
 
 APP_NAME = 'yamllint'
-APP_VERSION = '1.25.0'
+APP_VERSION = '1.26.3'
 APP_DESCRIPTION = __doc__
 
 __author__ = u'Adrien Vergé'

yamllint/linter.py

@@ -233,7 +233,7 @@ def run(input, conf, filepath=None):
     if conf.is_file_ignored(filepath):
         return ()
 
-    if isinstance(input, (type(b''), type(u''))):  # compat with Python 2 & 3
+    if isinstance(input, (bytes, str)):
         return _run(input, conf, filepath)
     elif hasattr(input, 'read'):  # Python 2's file or Python 3's io.IOBase
         # We need to have everything in memory to parse correctly

yamllint/rules/braces.py

@@ -22,7 +22,8 @@ braces (``{`` and ``}``).
 
 * ``forbid`` is used to forbid the use of flow mappings which are denoted by
   surrounding braces (``{`` and ``}``). Use ``true`` to forbid the use of flow
-  mappings completely.
+  mappings completely. Use ``non-empty`` to forbid the use of all flow
+  mappings except for empty ones.
 * ``min-spaces-inside`` defines the minimal number of spaces required inside
   braces.
 * ``max-spaces-inside`` defines the maximal number of spaces allowed inside
@@ -60,6 +61,18 @@ braces (``{`` and ``}``).
 
     object: { key1: 4, key2: 8 }
 
+#. With ``braces: {forbid: non-empty}``
+
+   the following code snippet would **PASS**:
+   ::
+
+    object: {}
+
+   the following code snippet would **FAIL**:
+   ::
+
+    object: { key1: 4, key2: 8 }
+
 #. With ``braces: {min-spaces-inside: 0, max-spaces-inside: 0}``
 
    the following code snippet would **PASS**:
@@ -128,7 +141,7 @@ from yamllint.rules.common import spaces_after, spaces_before
 
 ID = 'braces'
 TYPE = 'token'
-CONF = {'forbid': bool,
+CONF = {'forbid': (bool, 'non-empty'),
         'min-spaces-inside': int,
         'max-spaces-inside': int,
         'min-spaces-inside-empty': int,
@@ -141,7 +154,15 @@ DEFAULT = {'forbid': False,
 
 
 def check(conf, token, prev, next, nextnext, context):
-    if conf['forbid'] and isinstance(token, yaml.FlowMappingStartToken):
+    if (conf['forbid'] is True and
+            isinstance(token, yaml.FlowMappingStartToken)):
+        yield LintProblem(token.start_mark.line + 1,
+                          token.end_mark.column + 1,
+                          'forbidden flow mapping')
+
+    elif (conf['forbid'] == 'non-empty' and
+            isinstance(token, yaml.FlowMappingStartToken) and
+            not isinstance(next, yaml.FlowMappingEndToken)):
         yield LintProblem(token.start_mark.line + 1,
                           token.end_mark.column + 1,
                           'forbidden flow mapping')

yamllint/rules/brackets.py

@@ -22,7 +22,8 @@ inside brackets (``[`` and ``]``).
 
 * ``forbid`` is used to forbid the use of flow sequences which are denoted by
   surrounding brackets (``[`` and ``]``). Use ``true`` to forbid the use of
-  flow sequences completely.
+  flow sequences completely. Use ``non-empty`` to forbid the use of all flow
+  sequences except for empty ones.
 * ``min-spaces-inside`` defines the minimal number of spaces required inside
   brackets.
 * ``max-spaces-inside`` defines the maximal number of spaces allowed inside
@@ -61,6 +62,18 @@ inside brackets (``[`` and ``]``).
 
     object: [ 1, 2, abc ]
 
+#. With ``brackets: {forbid: non-empty}``
+
+   the following code snippet would **PASS**:
+   ::
+
+    object: []
+
+   the following code snippet would **FAIL**:
+   ::
+
+    object: [ 1, 2, abc ]
+
 #. With ``brackets: {min-spaces-inside: 0, max-spaces-inside: 0}``
 
    the following code snippet would **PASS**:
@@ -129,7 +142,7 @@ from yamllint.rules.common import spaces_after, spaces_before
 
 ID = 'brackets'
 TYPE = 'token'
-CONF = {'forbid': bool,
+CONF = {'forbid': (bool, 'non-empty'),
         'min-spaces-inside': int,
         'max-spaces-inside': int,
         'min-spaces-inside-empty': int,
@@ -142,7 +155,15 @@ DEFAULT = {'forbid': False,
 
 
 def check(conf, token, prev, next, nextnext, context):
-    if conf['forbid'] and isinstance(token, yaml.FlowSequenceStartToken):
+    if (conf['forbid'] is True and
+            isinstance(token, yaml.FlowSequenceStartToken)):
+        yield LintProblem(token.start_mark.line + 1,
+                          token.end_mark.column + 1,
+                          'forbidden flow sequence')
+
+    elif (conf['forbid'] == 'non-empty' and
+            isinstance(token, yaml.FlowSequenceStartToken) and
+            not isinstance(next, yaml.FlowSequenceEndToken)):
         yield LintProblem(token.start_mark.line + 1,
                           token.end_mark.column + 1,
                           'forbidden flow sequence')

yamllint/rules/line_length.py

@@ -17,10 +17,6 @@
 """
 Use this rule to set a limit to lines length.
 
-Note: with Python 2, the ``line-length`` rule may not work properly with
-unicode characters because of the way strings are represented in bytes. We
-recommend running yamllint with Python 3.
-
 .. rubric:: Options
 
 * ``max`` defines the maximal (inclusive) length of lines.
@@ -144,7 +140,11 @@ def check(conf, line):
                 start += 1
 
             if start != line.end:
-                if line.buffer[start] in ('#', '-'):
+                if line.buffer[start] == '#':
+                    while line.buffer[start] == '#':
+                        start += 1
+                    start += 1
+                elif line.buffer[start] == '-':
                     start += 2
 
                 if line.buffer.find(' ', start, line.end) == -1:

yamllint/rules/quoted_strings.py

@@ -144,6 +144,17 @@ def VALIDATE(conf):
 
 DEFAULT_SCALAR_TAG = u'tag:yaml.org,2002:str'
 
+# https://stackoverflow.com/a/36514274
+yaml.resolver.Resolver.add_implicit_resolver(
+    'tag:yaml.org,2002:int',
+    re.compile(r'''^(?:[-+]?0b[0-1_]+
+               |[-+]?0o?[0-7_]+
+               |[-+]?0[0-7_]+
+               |[-+]?(?:0|[1-9][0-9_]*)
+               |[-+]?0x[0-9a-fA-F_]+
+               |[-+]?[1-9][0-9_]*(?::[0-5]?[0-9])+)$''', re.X),
+    list('-+0123456789'))
+
 
 def _quote_match(quote_type, token_style):
     return ((quote_type == 'any') or